Alertness, Sleep and Attention

• Faculty of Medicine, Helwan National University
• Academic Year: 2024-2025
• Year: 1
• Semester: 2
• Module: Locomotor system (Ics) 105
• By: Dr. Haytham Hasan, Associate Professor
• Department of Neuropsychiatry

Objectives

• Understand alertness & sleep
• Explain attention mechanisms
• Describe memory processes

Alertness

• Alertness is a state of full awareness of the surroundings.
• Alertness is measured by the Glasgow Coma Scale.
• Factors determining alertness include individual physical, emotional, and mental state.
• Environment factors that determine alertness include illumination and noise.

States

• Sleep is an active circadian physiological alteration of alertness used for physical and psychological restoration.

Sleep Cycle

• A pattern of electrochemical changes in the brain occurs every 2 hours of sleep.
• Short sleepers (6 hours/night) experience 3 cycles.
• Long sleepers (8 hours/night) experience 4 cycles per night.
• Non-Rapid eye movement has 4 sub-stages
• Stages include Rapid eye movement and non-REM.
• Non-REM occurs at the beginning and end of each sleep cycle
• REM sleep occurs in the middle of each sleep cycle
• Non-REM why: Physical restoration
• REM Sleep why: Psychological restoration Dreams
• Stage 1 : 5 minutes
• Stage 2 : 20 minutes
• Stage 3 : 30 minutes
• Stage 4 : N/A
• Theta waves appear in EEG during stage 1.
• Sleep spindles appear during stage 2.
• Delta waves appear during stage 3.
• Delta waves predominate during stage 4.
• Most dreaming occurs near dawn, since the ratio of REM sleep increases throughout the night.

Dreams

• Dreams can be described as mental experiences that occur during the REM stage of sleep.
• Dreams involve images and ideas unbound by logical thinking.
• Intense emotions are possible during dreams.
• Unpleasant dreams can be called nightmares.

Dream Explanations

• Biological School: Electrochemical changes
• Cognitive School: Brain interprets stimuli perceived in altered awareness.
• Analytical School: Freud postulated that dreams symbolize and fulfill repressed wishes in our past.

Sleep in Vulnerable Groups

• Infants sleep longer (16 hours) and show greater REM.
• Elderly have decreased REM sleep.
• Pregnant women have increased sleep duration, especially in the 1st 3 months of pregnancy.
• Medical illnesses such as hypothyroidism increase sleep, while thyrotoxicosis decreases sleep.
• Psychiatric illnesses such as depression increase sleep, while anxiety and painful conditions decrease sleep.
• Sleep debt is the duration of sleep increases if sleep deprivation occurs the day before.
• Sleep deprivation can cause serious mental and physical consequences.
• A sleep laboratory is equipped with EEG, EMG, ECG, respiratory function tests, and video to diagnose sleep disorders.

Attention

• Attention is the process by which stimuli are selected for further processing while neglecting others.
• Thalamo-cortical connections, mainly frontal, are responsible for attention.
• This process could be spontaneous involuntary or voluntary i.e. intended concentration on a stimulus

Attention Types

• Attention span is a concentration sustained attention, affected in ADHD.
• Shifting attention involves moving from task to task under voluntary control, affected in mania.
• Dividing attention may be sequential, one task after another, or parallel, several tasks at once, affected in anxiety.
• Attention can be affected by illness or exhaustion.

Factors Increasing Attention

• Individual attributes: physical and emotional state (drives and needs) and mental expectations.
• Stimulus attributes: intensity, size, contrast, repetition, motion, novelty, and familiarity.

Memory

• Memory is a process by which information is stored.
• Multiple regions in the temporal lobe are involved in memory.

Memory Involves 3 Steps

• Encoding means putting information into memory and electrochemical changes when information comes from sensory input.
• Registration involves holding encoded information in memory until time of retrieval, be it short or long term memory.
• Retrieval involves using information stored in memory.

Memory Types

• Short term memory has a limited duration of 15-20 seconds and a limited capacity of 7±2 bits of information. Short term memory involves reverberating circuits.
• Long term memory has a lifelong duration and a huge capacity. Long term memory involves DNA and protein synthesis.

Memory Functions

• Short term memory handles current information until important parts are chosen for consolidation in long term memory.
• Long term memory includes procedural, semantic, and episodic storage.

Factors Improving Memory

• Individual attributes: includes a physical, emotional, and mental state
• Attributes of Meaningful memories: organized (rhyming, mind map, chunking, chaining) and rehearsed and repeated.

Disorders of Memory

• Amnesia (Forgetting) is due to failure of encoding (dementia, anxiety), registration (head trauma & narcotics) or retrieval (dissociative disorders) or also interference.
• Proactive interference: old memories cause difficulty with new ones.
• Retroactive interference: new memories impair old ones.
• False memory syndrome: remembering distorted things that didn't happen under the effect of suggestion.

Perception

• Perception can be defined as a mental process of interpreting sensory stimuli, or it is the process by which we integrate primary simple stimuli into secondary complex sets of stimuli
• Percepts are the images of objects or voices.

Perception Stages

• Segregation of object from background
• Localization
• Motion determination

Factors Affecting Perception

• Individual: (top-down processing) as to physical, emotional and mental state
• Stimulus organization: (bottom-up processing)

Gestalt

• Gestalt perception is to perceive stimuli as a whole where every detail influence the perception
• Similarity: Similar symmetrical stimuli are organized together
• There is a tendency of closure and continuity of missing details.

Vision

• Relative size
• Superposition
• Height in field & linear intersections implies depth in monocular vision.
• In binocular vision, two different retinal images from different angles imply depth.

Motion

• Consecutive switch on and off of lamps implies a spark is moving along lamps, known as stroboscopic motion
• Induced motion occurs when a large object moves with a small one static.

Thinking

• A mental activity that goes on in the brain when a person is organizing or communication information to others.
• Thinking doesn't depend directly upon contact with the immediate physical environment.
• Thinking can be considered “Language of the Mind".
• It is the process by which we associate percepts to form concepts (mental representations) and attributes (properties of concepts).
• Concepts are the building blocks of mental representations and thoughts.
• A concept is the idea referred to objects such as mental categories we form to group objects, events or situations that share common characteristics or features.
• Attributes are the elements of stimuli which are abstracted to enable formation of concepts.
• A problem is a gap between what one finds and what one wishes, which is decreased by a solution until it vanishes.

Types of Thinking

• Primary Magical - Aim: gratify wishes - Technique: imaginative play/daydreams.
• Critical Logical - Aim: problem solving - Technique: algorithms.
• Parallel Creative - Aim: invention - Technique: heuristics

Brain Components

• Prefrontal cortex and its connections to parieto-temporal association areas are responsible for thinking.

Disorders of Thinking

• Content is ideas themselves, and associations of percepts are disrupted by illness.
• Form or process is continuity of ideas; associations are disrupted, and there is discontinuity of ideas.

Language

• Language is a system of symbols to communicate ideas.
• listening, speaking, reading, writing
• Language consists of: phonemes (spoken words), morphemes (written words), semantics (meanings), syntax (grammar) and pragmatics (context)

Language Development

• Skinner postulates that language development occurs by operant learning.
• Chomsky postulates a brain imprinted language acquisition device (LAD)

Milestones of Language Development

• During the first year, babbling laryngeal sounds
• 1-2 years, vocabulary of around 25 words
• 2-3 years, 2 word sentences
• 4 years and above use grammatical words

Requirements for Intact Thought

• Auditory apparatus (ear)
• Auditory pathway
• 1ry & 2ry Auditory cortex
• Wernick's area (receptive).
• Broca's or Exner's area (expressive).
• motor cortex with extra-pyramidal & cerebellar modulation.
• motor pathways to speech apparatus
• Speech apparatus: oral cavity (lips, cheeks, jaw, teeth, tongue, pharynx, palate) respiratory system (nose, larynx, trachea, bronchi and lungs) diaphragm and abdominal muscles.

Delayed Language

• Thorough assessment is required:
• Ear
• Speech apparatus,
• Nervous system
• IQ assessment,
• specific assessment of child's behavior to rule out autism.
• Assessment of emotional disorders.

Abilities

• Achievement is actual
• Capacity is potential
• Aptitude is predicted

Intelligence

• Intelligence is the ability to learn and adapt to the environment.
• Spearman intelligence is measurable as a general factor.
• William Stern offered the intelligence quotient as IQ = (mental age / chronologic age) x 100

Tests to Measure IQ

• Stanford binet test
• Wechsler intelligence test